Near Field Communication, or NFC as it is known to the person skilled in the art, is a wireless connectivity technology which enables a communication over a short distance, for example 10 cm, between electronic devices, such as, for example, contactless chip cards or mobile telephones in card emulation mode, and readers.
NFC technology is particularly suitable for connecting any type of user device and enables fast and simple communications.
A contactless device is a device capable of exchanging information via an antenna with another contactless device, for example a reader, according to a contactless communication protocol.
An NFC device, which is a contactless device, is a device compatible with NFC technology.
NFC technology is an open technological platform standardized in the ISO/IEC 18092 and ISO/IEC 21481 standards, but incorporates many existing standards such as, for example, the type-A and type-B protocols defined in the ISO-14443 standard which may be communication protocols usable in NFC technology.
In addition to its conventional telephony function, a cellular mobile telephone can be used (if it is equipped with specific circuitry) to exchange information with another contactless device, for example a contactless reader, using a contactless communication protocol usable in NFC technology.
This enables information to be exchanged between the contactless reader and secure elements located in the mobile telephone. Many applications are thus possible, such as mobile ticketing in public transport (the mobile telephone acts as a travel ticket) or mobile payment (the mobile telephone acts as a payment card).
Different electronic circuits can be integrated in a compact manner and can jointly occupy the same chip or can coexist on the same device or platform. These circuits share the same substrate, the same signals, the same supply signals and the same clock signal tree structures.
This results in electromagnetic stray coupling which must be taken into account in the integrated circuit design.
Furthermore, the intrinsic non-linearity of active analog and digital devices causes out-of-band interference (mainly high-order harmonics), which causes a severe distortion, particularly in the other wanted analog signals, and also voltage or direct current offset errors on sensitive nodes in the victim circuit, resulting in malfunction of the latter.